Apparatus for displaying the relationship between four signals

ABSTRACT

An apparatus for displaying the mutual relationship of four electric signals in one figure pattern, which is displayed on the screen of a cathode-ray tube by rectifying the four electric signals by a rectifying circuit, and applying each of the rectified signals to the horizontal deflecting electrodes and the vertical deflecting electrodes of the cathode-ray tube, said apparatus displaying the balance of a four channel stereophonic device when the four electric signals are the audio frequency signals of a four channel stereophonic device.

United States Patent [191 Odagi Apr. 23, 1974 APPARATUS FOR DISPLAYING THE RELATIONSHIP BETWEEN FOUR SIGNALS [75] Inventor:

[73] Assignee: Matsushita Electric Industrial Co.

Ltd., Osaka-fu, Japan [22] Filed: June 19, 1972 [21] Appl. No.: 264,061

Kanji Odagi, Osaka, Japan [30] Foreign Application Priority Data June 22, 1971 Japan 46-45510 [52] US. Cl. 179/1 GQ, 315/18 [51] Int. Cl H04! 5/00 [58] Field of Search 179/1 VS, 1 G, 1 GO; 324/88, 98, 121; 315/25, 18

[56] References Cited UNITED STATES PATENTS 3,524,998 8/1970 Gilbert 315/18 2,500,646 3/l950 Riesz 179/1 VS OTHER PUBLICATIONS A Quadraphonic Oscilloscope Display Technique by Patten, Journal of Audio Engineering Society presented May 3, 1972 at 42nd Convention of the Audio Engineering Society, p. 483-489.

Primary Examiner-Kathleen H. Claffy Assistant ExaminerDouglas W. Olms Attorney, Agent, or FirmWenderoth, Lind & Ponack [5 7] ABSTRACT An apparatus for displaying the mutual relationship of four electric signals in one figure pattern, which is displayed on the screen of a cathode-ray tube by rectifying the four electric signals by a rectifying circuit, and applying each of the rectified signals to the horizontal deflecting electrodes and the vertical deflecting electrodes of the cathode-ray tube, said apparatus displaying the balance of a four channel stereophonic device when the four electric signals are the audio frequency signals of a four channel stereophonic device.

10 Cla ms 1 Drawing li a us xaoama PATENTEM 2 74 SHEET 2 [IF 5 FIG. 6

: APR 23 m4 SHEET S []F 5 FIG /3 FIG. /4

APPARATUS FOR DISPLAYING THE RELATIONSHIP BETWEEN FOUR SIGNALS This invention relates to an apparatus for displaying the ralationship between four signals used in a system wherein the four signals are simultaneously handled.

In general, the relationship between four electric signals has been heretofore determined by means of a four-phenomena oscilloscope. However, in such a fourphenomema oscilloscope, the four signal waves are displayed on the screen individually and separately. Therefore, this conventional method is not suitable for continuous observation over a long period.

Accordingly, one object of the present invention is to provide an apparatus for observing the amplitude and phase relationships between four electric signals, which is simple in construction and makes observation easy.

Another object of the invention is to provide an apparatus for displaying the mutual relationship between four electric signals in one figure pattern.

A further object of the invention is to provide an apparatus for displaying the mutual relationship between electric signals which are at the front and back of both the left hand side and the right hand side of a four channel stereophonic device by an apparatus of simple construction.

A still further object of the invention is to display the balance of a stereophonic device in a single figure by an apparatus of simple construction.

These and other objects and features of the present invention will become apparent from the description of preferred embodiments thereof, with reference to the attached drawings, in which;

FIG. 1 is a diagram showing the basic constitution of an embodiment of the invention,

FIG. 2 and FIG. 6 are diagrams illustrating the application of the present invention to a four channel stereophonic device,

FIGS. 3a, 3b, 3c, 3d, and 3e are graphs showing the figure pattern obtained by the present invention,

FIGS. 4 and 5 and FIGS. 7 through are diagrams showing the constitution of other embodiments of the present invention.

Although this invention will be described with regard to the display of a four-channel stereophonic device wherein a sound field is reproduced with four speakers, this invention may be similarly applied to the display of four signals of other kinds.

Referring now to FIG. 1, the figure shows a basic structure of the displaying apparatus of this invention. Four rectifying circuits, 1, 2, 3 and 4 rectify four electric signals A, B, C and D respectively. An electrostatic deflection-type cathode-ray tube 5 has positive and negative Y-axis deflecting electrodes 6 and 7 and positive and negative X-axis deflecting electrodes 8 and 9.

In FIG. 1, the four signals A, B, C and D are rectified to half waves of positive polarities by the rectifying circuits 1, 2, 3 and 4 respectively, and the rectified signals are supplied to the respective deflecting electrodes 6, 8, 9 and 7. When only signal A is present and the other signals B, C and D are absent, only the rectified signal A is supplied to the deflecting electrode 6. As a result, the figure pattern displayed on the screen of the cathode-ray tube 5 is as shown in FIG. 3 (11). Thus, when the apparatus is used for a four-channel stereophonic device, the figure patterns displayed on the screen of the cathode-ray tube 5 represent the sound fields in the four-channel stereophonic device. More specifically, when four speakers 10, ll, 12 and 13 are, arranged as shown in FIG. 2, reproduced sound comes from the front of the device when only signal A is present, the corresponding figure pattern displayed on the screen of the cathode-ray tube indicates the direction of the sound field.

An, explanation will now be given of the case where only the signals A and B are present, and the signal A is equal to the signal B. In this case, the same voltage of positive polarity is supplied to the deflecting electrodes 6 and 8, and thus the figure pattern on the cathode-ray tube 5 is as shown in FIG. 3 (b). In this case, the sound field in the four-channel stereophonic device is intermediate between the speakers 10 and 11, and the figure shown in FIG. 3 (b) indicates the direction of the sound field.

When only three signals A, B and C are present, and they are equal to one another the same voltage of positive polarity is supplied to the deflecting electrodes 6, 8 and 9, and thus a figure pattern as shown in FIG. 3 (a) is displayed on the screen of the cathode-ray tube 5. More specifically, since deflecting actions by the deflecting electrodes 8 and 9 counterbalance one another, and only deflecting action by the deflecting electrode 6 remains effective, the figure pattern displayed on the screen of the tube 5 is as shown in FIG. 3 (a). In this case, the sound field of the stereophonic device lies in the front thereof, and thus the figure pattern as shown in FIG. 3 (a) indicates the direction of the sound field.

When four signals A, B, C and D are all present and all equal the deflecting actions by the deflecting electrodes counterbalance one another and thus the figure pattern displayed on the screen of the tube 5 is as shown in FIG. 3 (c). In this case, the sound field of the four-channel stereophonic device lies in the center of the speakers 10, 11, 12 and 13 and correspondingly the figure displayed on the tube 5 indicates the direction of the sound field.

When only two signals A and B are present, and they are of equal amplitude, but are out of phase by to each other, the shape of the figure displayed on the screen of the tube 5 becomes a sector as shown in FIG. 3 (d). In this case, the sound field of the four-channel stereophonic device spreads in the space between the speakers 10 and 1 l. The figure pattern displayed on the tube 5 effectively indicates the corresponding sound field in this case. Finally, when the four signals A, B, C and D are present and they are unrelated to one another in amplitude and frequency, the figure pattern on the screen of the tube 5 is as shown in FIG. 3 (e). In this case, the sound field of the four-channel stereophonic device spreads over the whole area. Thus the figure pattern as shown in FIG. 3 (e) indicates the sound field in this case.

According to the above embodiments, all of the relationships between the four signals A, B, C and D can be displayed by simple figure patterns. These displayed figure patterns are more easily comprehensible compared with conventional displayed figure patterns. Furthermore, when the apparatus of the invention is used for a four-channel stereophonic device, the sound fields in the device can be effectively represented by the figure patterns themselves on the screen of the cathode-ray tube as mentioned above. In addition, according to the above embodiment, the construction of the apparatus is simple and does not require any timeaxis sweep signal generating circuit and sweep-trace blanking circuit.

While the rectified signals of positive polarity are applied to the deflecting electrodes 6, 7, 8 and 9 in this embodiment, it should be understood that rectified signals of negative polarity may be applied to the deflecting electrodes.

FIGS. 4, and 7 to show schematically other embodiments of the invention. In these figures, the parts similar to those of the embodiment of FIG. 1 are indicated by the same reference numbers as used in FIG. 1.

In the embodiment shown in FIG. 4, four signals A, B, C and D are half-wave rectified by means of rectifying circuits 1, 2, 3 and 4 consisting of diodes 14, l5, l6 and 17, and resistors 18, 19, and 21. These rectified signals are amplified by means of D.C. amplifiers 22, 23, 24 and 25, and then the amplified signals are applied to deflecting electrodes 6, 8, 9 and 7.

In another embodiment shown in FIG. 5, four signals A, B, C and D are converted into signals of positive and negative polarities by means of phase inverter circuits 26, 27, 28 and 29. These converted signals are rectified by means of rectifying circuits 1, 2, 3 and 4 consisting of diodes 30 through 37 and resistors 38 through 41, and then the rectified signals are applied to deflecting electrodes 6, 8, 9 and 7. The combination of the phase inverter circuit 26, the pair of diodes 30 and 31, and the resistor 38 compose a full-wave rectifying device. The other combinations of the phase inverter circuits 27 through 29, diodes 32 through 37, and resistors 39 through 41 similarly compose full-wave rectifying devices. In the embodiment shown in FIG. 5, the deflecting electrodes 6, 8, 9 and 7 of the cathode-ray tube 5 are rotated through 45. This allows the displaying apparatus of FIG. 5 to be used for the display for a fourchannel stereophonic device in which four speakers 10, 11, 12 and 13 are arranged as shown in FIG. 6.

In another embodiment of FIG. 7, four signals A, B, C and D are amplified by means of A.C. amplifiers 42, 43, 44 and 45. Then, the amplified signals are halfwave rectified by means of rectifying circuits 1 to 4 consisting of diodes 14 to 17 and resistors 18 to 21. The rectified signals are applied to deflecting electrodes 6, 8, 9 and 7. In this embodiment, the deflecting electrodes 6, 8, 9 and 7 are arranged in a special manner. From this embodiment, it will be understood that the deflecting electrodes 6, 8, 9 and 7 may be arranged in any special manner, if necessary.

In another embodiment shown in FIG. 8, compensating circuits 46, 47, 48 and 49, the transmission characteristics of which vary in accordance with the frequency or duration of signals, are inserted in front of rectifying circuits 1, 2, 3 and 4 to obtain required compensation of figure patterns appearing on the cathoderay tube. The objects and features of the compensation are as follows. The sensitivity of the deflection of the cathode ray tube, for example, is generally lowered for high frequency signals. However, a good linearity of the sensitivity can be obtained over a wide frequency range by increasing the amplitude of high frequency signals with the compensating circuit. Further, especially in the application to a four-channel stereophonic device, the compensating circuit is suitably used for compensating the display to match the frequency and transiency response of mans hearing.

In a further embodiment, shown in FIG. 9, rectifying circuits 1, 2, 3 and 4 consisting of diodes 14, 15, 16 and 17, resistors 18, 19, 20 and 21, and capacitors 50, 51, 52 and 53, eliminate deflections due to higher harmonic wave components, resulting in a clearer display.

In another embodiment, shown in FIG. 10, rectifying circuits 1, 2, 3 and 4 generate rectified outputs of oppisite polarities at their outputs. Then the rectified outputs of opposite polarities are added by mixing circuits 54 and 55. These mixed signals are applied to the deflecting electrodes 6 and 8 of the cathode-ray tube. This embodiment is basically equivalent to the embodiment of FIG. 1. In other words, the application of signals of opposite polarities to the deflecting electrodes 6 and 8 is equivalent to the application of signals of the same polarity to the deflecting electrodes 7 and 9. This embodiment has advantages in that the deflecting circuit is simplified and thus the displaying apparatus is inexpensive and useful for industrial applications.

FIG. 11 shows more specifically the embodiment of FIG. 10. The rectifying circuits 1, 2, 3 and 4 consist of diodes 14, 15, 16 and 17 and the mixing circuits 54 and 55 consist of resistors 56, 57, 58 and 59, 60, 61.

In another embodiment shown in FIG. 12, the defleeting electrodes 6, 7, 8 and 9 of a cathode-ray tube 5 are either horizontally or vertically arranged. Nevertheless, the tube 5 can display figure patterns equivalent to those in a device in which the deflecting electrodes of the tube are effectively rotated 45 according to this embodiment. More specifically, a signal A is rectified by a rectifying circuit 1 and then applied through mixing circuits 62 and 63 to the deflecting electrodes 6 and 9. Signal B is rectified by rectifying circuit 2 and then applied through the mixing circuits 62 and 65 to the deflecting electrodes 6 and 8. Signal C is rectified by rectifying circuit 3 and then applied through the mixing circuits 63 and 64 to the deflecting electrodes 9 and 7. Signal D is rectified by a rectifying circuit 4 and then applied through the mixing circuits 64 and 65 to the deflecting electrodes 7 and 8. Each of these four mixing circuits composes (or produces) one output signal by adding two input signals. According to this arrangement, the beam in the tube 5 can be deflected upward to the left by signal A, and upward to the right, downward to the left and downward to the right by signals B, C and D.

Another embodiment shown in FIG. 13 is a simplified version of that of FIG. 12. This embodiment is characterized in that D.C. amplifiers 66 and 67, which can be operated in response to differential inputs, are employed. Signal A is applied through rectifying circuit 1 to the different inputs of the D.C. amplifiers 66 and 67. The signal A applied to the positive input of the D.C. amplifier 66 is amplified by the amplifier 66 and then applied to the deflecting electrode 6, and the signal A applied to the negative input of the D.C. amplifier 67 is inverted in phase by the amplifier 67, and then applied to the deflecting electrode 8. This is effectively the same as if signal A is applied to the deflecting electrodes 6 and 9 without being inverted in phase, and the signal A deflects the beam in the tube 5 upward to the left. Deflections of the beam in the tube 5 upward to the right, downward to the left and downward to the right can be effected by signals B, C and D through similar procedures.

Another embodiment, shown in FIG. 14, is equivalent to that of FIG. 13. In this embodiment, three phase-inverter circuits 68, 69 and 70, and six rectifying circuits 71, 72, 73, 74, 75 and 76 are employed. Mixing circuits 77 and 78 are also employed. Each of these mixing circuits composes (or produces) one output signal by adding four input signals.

In another embodiment shown in FIG. 15, a circuit,

79, is added to the structure of FIG. 1. The circuit 79 is a mixing device and the four rectified signals are added by this mixing device. The purpose of the circuit 79 is to control the brightness or color of figure patterns on the tube 5 according to the frequencies or amplitudes of signals. For example, when all the signals A, B, C and D are absent, the figure pattern will be a central spot, as illustrated in FIG. 3 (c). As is known in the art, if such a state lasts for a long time, the fluorescent screen of the cathode-ray tubemay be damaged. In such a case where no deflection signals are present, the fluorescent screen can be protected from damage due to the central spot by weakening the brightness or by switching off the central spot by means of the circuit 79. Further, in a cathode-ray tube having a tri-color fluorescent screen, the figure patterns can be displayed in red for high frequency signals, in blue for low frequency signals, and in green for middle frequency signals, by means of the circuit 79. The cathode-ray tube 5 has another electrode 80 thereon.

As will be apparent from the embodiments as described above, the displaying apparatus according to this invention, wherein four signals are rectified and the light spot of the cathode-ray tube is deflected in independent directions corresponding to the various rectified signals, has advantages in that the relationships between the four signals can be represented by a single figure pattern and a clearer display can be obtained. When the displaying apparatus of this invention is applied to a four-channel stereophonic device, a sound field in the device can be effectively indicated by a figure pattern in the displaying apparatus.

While an electrostatic deflection type cathode-ray tube has been utilized in the embodiments mentioned above, it should be understood that an electromagnetic deflection type cathode-ray tube may be similarly utilized.

I claim:

1. An apparatus for displaying the relationship between four electric signals, comprising a cathode ray tube including deflection means capable of deflecting an electron beam of said tube in four directions; four rectifying devices, each of said rectifying devices having an input and an output, the output of each of said rectifying devices being connected to said deflection means and the input of each of said rectifier means being adapted to be connected to a different one of said four electric signals, whereby said four electric signals can be recitified by said four rectifying devices, and said electron beam in said cathode ray tube can be deflected in four directions by said rectified signals so as to display a single figure pattern on said cathode ray tube which represents the mutual relations between said four electric signals.

2. An apparatus according to claim 1, wherein signals of each channel of a four channel stereoph'onic device are used as said four electric signals whereby said apparatus displays the balance of said signals.

3. An apparatus according to claim 1, wherein each of said four rectifying devices is a half wave rectifying circuit comprising a diode and a resistance.

4. An apparatus according to claim 1 wherein a compensating circuit, the transmission characteristics of which are varied in accordance with the frequency and transiency of signals applied thereto, is inserted in front of each of said rectifying devices thereby more closely simulating the frequency and transiency response of mans hearing.

5. An apparatus according to claim 1, wherein each of said rectifying devices comprise a diode, a resistance and a condenser.

6. An apparatus according to claim 1, wherein the four rectified signals from said four rectifying devices are added by a mixing device, and the output of said mixing device is supplied to an electrode of said cathode-ray tube to control the brightness and color of the figure patterns on said cathode-ray tube.

7. An apparatus for displaying the relationships between four electric signals comprising means adapted to be connected to four electric signal sources, four rectifying devices for rectifying said electric signals from said electric signal sources, two mixing devices for adding two rectified signals obtained by said rectifying devices and a cathode-ray tube having at least two adjacent deflecting electrodes, two of said rectifying devices being of opposite polarity to the other two rectifying devices, whereby each pair of rectified signals of opposite polarity to the other two, obtained by said rectifying devices, are added by said mixing devices, and the two added signals obtained by said mixing devices are applied to said two adjacent deflecting electrodes of said cathode ray tube.

8. An apparatus for displaying the relationships between four electric signals comprising means adapted to be connected to four electric signal sources, first, second, third and fourth rectifying devices; first, second, third, and fourth mixing devices for adding two rectified signals obtained by said rectifying devices; and a cathode-ray tube having four deflecting electrodes, wherein four electric signals from said electric signal sources are rectified by said first through fourth rectifying devices, and the rectified signals obtained by said first and second rectifying devices are added by said first mixing device, the rectified signals obtained bysaid first and third rectifying devices are added by said second mixing device, the rectified signals obtained by said third and fourth rectifying devices are added by said third mixing device and the rectified signals obtained by said second and fourth rectifying devices are added by said fourth mixing device, and the mixed signals obtained by said first and second mixing devices are applied respectively to an adjacent pair of said deflecting electrodes and the mixed signals obtained by said third and fourth mixing devices are applied respectively to the other adjacent pair of said deflecting electrodes.

9. An apparatus for displaying the relationships between four electric signals, comprising means adapted to be connected to four electric signal sources, first, second, third and fourth rectifying devices, first and second D.C. amplifiers and a cath ode-ray having at least two adjacent deflecting electrodes, each of said amplifiers having a positive and a negative input, wherein four electric signals from said signal sources are rectified by said first through fourth rectifying devices, the rectified signal obtained by said first rectifying device is supplied to the positive input of said first D.C. amplifier and to the negative input of said second D.C. amplifier, the rectified signal obtained by said second rectifying device is applied to the positive input of said first D.C. amplifier and to the positive input of said second D.C. amplifier, the rectified signal obtained by said third rectifying device is applied to the negative input of said first D.C. amplifier and to the negative input of said second D.C. amplifier, the rectified signal obtained by said fourth rectifying device is applied to the positive input of said second D.C. amplifier and to the negative input of said first D.C. amplifier, and the outputs of said first and second D.C. amplifiers are applied to said two adjacent deflecting electrodes in said cathode-ray tube.

10. An apparatus for displaying the relationships between four electric signals comprising a cathode ray tube having four deflecting electrodes, means adapted to be connected to four sources of electric signals, four full wave rectifying devices, including phase inverting means for respectively rectifying the four electric signals from said sources of electric signals, and means for applying each output of said rectifying means respectively to said four deflecting electrodes of said cathode ray tube. 

1. An apparatus for displaying the relationship between four electric signals, comprising a cathode ray tube including deflection means capable of deflecting an electron beam of said tube in four directions; four rectifying devices, each of said rectifying devices having an input and an output, the output of each of said rectifying devices being connected to said deflection means and the input of each of said rectifier means being adapted to be connected to a different one of said four electric signals, whereby said four electric signals can be recitified by said four rectifying devices, and said electron beam in said cathode ray tube can be deflected in four directions by said rectified signals so as to display a single figure pattern on said cathode ray tube which represents the mutual relations between said four electric signals.
 2. An apparatus according to claim 1, wherein signals of each channel of a four channel stereophonic device are used as said four electric signals whereby said apparatus displays the balance of said signals.
 3. An apparatus according to claim 1, wherein each of said four rectifying devices is a half wave rectifying circuit comprising a diode and a resistance.
 4. An apparatus according to claim 1 wherein a compensating circuit, the transmission characteristics of which are varied in accordance with the frequency and transiency of signals applied thereto, is inserted in front of each of said rectifying devices thereby more closely simulating the frequency and transiency response of man''s hearing.
 5. An apparatus according to claim 1, wherein each of said rectifying devices comprise a diode, a resistance and a condenser.
 6. An apparatus according to claim 1, wherein the four rectified signals from said four rectifying devices are added by a mixing device, and the output of said mixing device is supplied to an electrode of said cathode-ray tube to control the brightness and color of the figure patterns on said cathode-ray tube.
 7. An apparatus for displaying the relationships between four electric signals comprising means adapted to be connected to four electric signal sources, four rectifying devices for rectifying said electric signals from said electric signal sources, two mixing devices for adding two rectified signals obtained by saId rectifying devices and a cathode-ray tube having at least two adjacent deflecting electrodes, two of said rectifying devices being of opposite polarity to the other two rectifying devices, whereby each pair of rectified signals of opposite polarity to the other two, obtained by said rectifying devices, are added by said mixing devices, and the two added signals obtained by said mixing devices are applied to said two adjacent deflecting electrodes of said cathode ray tube.
 8. An apparatus for displaying the relationships between four electric signals comprising means adapted to be connected to four electric signal sources, first, second, third and fourth rectifying devices; first, second, third, and fourth mixing devices for adding two rectified signals obtained by said rectifying devices; and a cathode-ray tube having four deflecting electrodes, wherein four electric signals from said electric signal sources are rectified by said first through fourth rectifying devices, and the rectified signals obtained by said first and second rectifying devices are added by said first mixing device, the rectified signals obtained by said first and third rectifying devices are added by said second mixing device, the rectified signals obtained by said third and fourth rectifying devices are added by said third mixing device and the rectified signals obtained by said second and fourth rectifying devices are added by said fourth mixing device, and the mixed signals obtained by said first and second mixing devices are applied respectively to an adjacent pair of said deflecting electrodes and the mixed signals obtained by said third and fourth mixing devices are applied respectively to the other adjacent pair of said deflecting electrodes.
 9. An apparatus for displaying the relationships between four electric signals, comprising means adapted to be connected to four electric signal sources, first, second, third and fourth rectifying devices, first and second D.C. amplifiers and a cathode-ray having at least two adjacent deflecting electrodes, each of said amplifiers having a positive and a negative input, wherein four electric signals from said signal sources are rectified by said first through fourth rectifying devices, the rectified signal obtained by said first rectifying device is supplied to the positive input of said first D.C. amplifier and to the negative input of said second D.C. amplifier, the rectified signal obtained by said second rectifying device is applied to the positive input of said first D.C. amplifier and to the positive input of said second D.C. amplifier, the rectified signal obtained by said third rectifying device is applied to the negative input of said first D.C. amplifier and to the negative input of said second D.C. amplifier, the rectified signal obtained by said fourth rectifying device is applied to the positive input of said second D.C. amplifier and to the negative input of said first D.C. amplifier, and the outputs of said first and second D.C. amplifiers are applied to said two adjacent deflecting electrodes in said cathode-ray tube.
 10. An apparatus for displaying the relationships between four electric signals comprising a cathode ray tube having four deflecting electrodes, means adapted to be connected to four sources of electric signals, four full wave rectifying devices, including phase inverting means for respectively rectifying the four electric signals from said sources of electric signals, and means for applying each output of said rectifying means respectively to said four deflecting electrodes of said cathode ray tube. 